Urethral catheter holder

ABSTRACT

A urethral catheter holder ( 10 ), comprising a supporting base ( 20 ); a suspension housing ( 22 ) mounted to supporting base ( 20 ); a catheter securement device ( 24 ) adapted to hold a catheter ( 30 ) passing longitudinally therethrough, catheter securement device ( 24 ) being adapted to slide longitudinally within suspension housing ( 22 ); and a biasing device ( 26 ) adapted to push a catheter guide ( 28 ) of catheter securement device ( 24 ) into engagement with the patient&#39;s external meatus (EM).

[0001] This application claims the benefit and priority of U.S. patentapplication Ser. No. 60/104,818, filed Oct. 19, 1998, the fulldisclosure of which is hereby incorporated by reference for allpurposes.

TECHNICAL FIELD

[0002] The present invention relates to catheter based pressure sensingsystems for diagnosing female urinary incontinence, and in particular tosystems for determining the relationship between urethral pressure andvesicle pressure in response to changes in abdominal pressure. Preferredaspects of the present invention relate to urethral catheter holdermechanisms.

BACKGROUND OF THE INVENTION

[0003] Female urinary incontinence can be evaluated by determining therelationship between a patient's urethral pressure and her vesicle(i.e.: bladder) pressure. Specifically, incontinence will occur when hervesicle pressure exceeds her urethral pressure. A continence margin canthus be defined by the difference between the patient's urethralpressure and the vesicle pressure.

[0004] Both urethral pressure and vesicle pressure will change inresponse to changes in abdominal pressure, however, the urethral andvesicle pressures may change at different rates as the abdominalpressure changes. Accordingly, incontinence may occur at variousabdominal pressures at which the vesicle pressure exceeds the urethralpressure. Incontinence can therefore be evaluated by producing apressuregram showing the relationship between the urethral pressure andthe vesicle pressure of the patient at different abdominal pressures.

[0005] Measuring the patient's vesicular and urethral pressures with apressure sensing catheter can be accomplished by moving a pressuresensor on the catheter from the patient's bladder, (at which the vesiclepressure is measured), through the patient's urethra (at which maximumurethral pressure is measured). Specifically, a urinary catheter withinternal or external pressure transducers can be used to take pressuremeasurements at the proximal urethra, mid-urethra, and distal urethra.Typically, such a pressure sensing catheter is first introduced throughthe urethra into the bladder. The pressure sensing catheter is thenwithdrawn through the urethra with pressure measurements taken at theproximal urethra (being 5-10 mm from the urethro-vesicular junction),the mid-urethra (being the point of maximum resting urethral pressure)and the distal urethra, (being 5-10 mm from the external meatus).

[0006] The measurements of the patient's vesicular and urethralpressures are preferably taken at various abdominal pressures. Suchdifferent abdominal pressures can conveniently be generated simply byhaving the patient cough with different amounts of effort. For example,a mild couch would generate a minimal increase in abdominal pressure,whereas a more intense cough will generate a greater abdominal pressure.The increase in abdominal pressure will cause both the urethral andvesicle pressures to increase.

[0007] Unfortunately, such coughing will also tend to cause movement ofthe patient's bladder and urethra. As such, it is difficult to maintainthe position of the pressure sensing catheter relative to the urethraduring the jarring movement of the urethra caused by the patientcoughing. Unwanted movement of the catheter relative to the urethracaused by the jarring action of the patient coughing tends to compromisethe accuracy of the pressure measurements.

[0008] It is important, therefore, to maintain the catheter at each ofthe desired measurement positions in the urethra when taking thepressure measurements. To date, an effective solution for maintainingthe position of the pressure sensing catheter at preferred locationsalong the urethra when the urethra moves in response to the patient'scough have not been found.

SUMMARY OF THE INVENTION

[0009] The present invention provides a female urethral catheter holderwhich is adapted to support a pressure sensing catheter such that thecatheter can be positioned at various desired locations along thepatient's urethra, allowing for the catheter to move in response tourethral movement, such that a pressure sensing transducer disposed onthe catheter does not move relative to the urethra when the patientcoughs.

[0010] In a preferred aspect of the present invention, the urethralcatheter holder comprises a supporting base, which is adapted toregister against the labia of the patient; a suspension housing mountedto the supporting base; a catheter securement device, (which is adaptedto move within the suspension housing when the patient coughs such thatthe catheter moves with the urethra); and a biasing device. In preferredaspects, the catheter securement device comprises a catheter guide whichis adapted to contact against the external meatus of the patient'surethra. The biasing device operates to provide a pre-loading force onthe catheter guide, thereby holding the catheter guide against theexternal meatus of the patient's urethra such that the cathetersecurement device moves with the movement of the urethra. Additionally,the biasing device operates to push the catheter securement deviceagainst the supporting base, thereby minimizing unwanted motion of thecatheter securement device within the suspension housing.

[0011] The catheter securement device is adapted to support the catheterin a manner such that the catheter moves in response to movement of theurethra, with the catheter remaining in generally the same positionrelative to the surrounding urethra when the patient coughs. In apreferred aspect, the catheter securement device comprises a torroidalballoon, a generally ring-shaped balloon support mount surrounding thetorroidal balloon and a pneumatic or hydraulic pressure tube forinflating or deflating the torroidal balloon. The catheter passeslongitudinally through the catheter holder and is received through theorifice defined by the torroidal balloon. Inflation of the torroidalballoon will cause it to expand radially inwardly such that it's centralorifice contracts, thereby gently pushing against the sides of thecatheter.

[0012] In other preferred aspects of the invention, the cathetersecurement device comprises a mechanical clamp which is mounted to movelongitudinally within the suspension housing.

[0013] Optionally, the present urethral catheter holder may alsocomprise a pair of leg straps, which can be wrapped around the patient'sthighs, (or a stretchable undergarment with leg straps attachablethereto), such that the supporting base of the catheter holder can beheld at a generally fixed position against the labia of the patient. Anadvantage of such leg straps is that pressure measurements can then betaken easily with the patient in different positions, including supineand sitting. An additional advantage of the present system is that itallows hands-free operation for the clinician.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is an exploded view of the urethral catheter holder.

[0015]FIG. 2 is a top view of the urethral catheter holder.

[0016]FIG. 3 is a front view of the urethral catheter holder.

[0017]FIG. 4 is a right-side view of the urethral catheter holder.

[0018]FIG. 5 is a rear view of the urethral catheter holder.

[0019]FIG. 6 is a sectional plan view of the urethral catheter holdertaken along line 6-6 in FIG. 5.

[0020]FIG. 7A is a sectional elevation view of the urethral catheterholder taken along line 7-6 in FIG. 5.

[0021]FIG. 7B is a view corresponding to FIG. 7A, but with a catheterreceived therethrough.

[0022]FIG. 8 shows positioning of the catheter holder by way of legstraps.

[0023]FIG. 9 shows positioning of the catheter holder by way of legstraps and a stretchable undergarment.

[0024]FIG. 10 is a schematic view of a system for evaluating femaleurinary incontinence incorporating the present urethral catheter holder.

[0025]FIG. 11 is an illustration of a pressuregram showing therelationship between the vesicle pressure and the urethral pressure fortwo different patients at different abdominal pressures.

[0026]FIG. 12 shows a mechanical clamp for use in the cathetersecurement device.

[0027]FIG. 13 shows a perspective view of an alternate embodiment of thepresent invention, comprising the mechanical clamp of FIG. 12.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0028] In preferred aspects of the present invention, a urethralcatheter holder is provided. FIG. 1 shows an exploded view of theassembly of urethra catheter holder 10, comprising a supporting base 20,a suspension housing 22, a catheter securement device 24, a biasingelement 26, and a catheter guide 28. Assembled views of catheter holder10 are shown in FIGS. 2, 3, 4, and 5. As shown in FIG. 2, a catheter 30is received longitudinally through catheter holder 10, as shown.

[0029] Catheter holder 10 is adapted to hold catheter 30 such thatsupporting base 20 can remain in contact with the patient's labia whilecatheter 30 moves longitudinally in response to movement of thepatient's urethra when the patient coughs. Accordingly, one advantage ofthe present invention is that catheter 30 can be positioned to remain inat the same relative location with respect to the patient's urethra whenthe patient coughs. The ability of catheter securement device 24 to holdcatheter 30 to allow for catheter movement in response to urethramovement, without tightly pinching catheter 30 is accomplished by thepresent novel catheter securement system, as follows.

[0030] Referring to FIGS. 6 and 7A, catheter securement device 24preferably comprises a torroidal balloon 41, a generally ring-shapedballoon support mount 42, a pneumatic or hydraulic pressure tube 43, anda catheter guide 28, as shown. Together, torroidal balloon 41, balloonsupport 42, pressure tube 43, and catheter guide 28 are adapted to slidelongitudinally as a unit within the suspension housing 22. A bushing 29,which may be made of Teflon, is provided to enable catheter guide 28 toslide freely through supporting base 20. Biasing element 26, which maypreferably comprise a mechanical spring, provides a pre-loading forcewhich gently pushes catheter guide 28 against the external meatus EM ofthe patient's urethra 50, (see FIG. 10). Accordingly, catheter guide 28will move together with the patient's urethra such that catheter guide28 identically tracks the movement of urethra 50.

[0031] As shown in FIG. 7B, catheter 30 is preferably received throughan opening 23 in suspension housing 22 and passes longitudinally throughcatheter holder 10, as shown. Torroidal balloon 41 is inflated by way ofpressure tube 43, which can be connected a pneumatic or a hydraulicpressure system (not shown). As torroidal balloon 41 is inflated, itscenter orifice will tend to close as the innermost sides of balloon 41expand inwardly, thereby gently pushing radially inwardly upon the sideof catheter 30 around its circumference, thus holding catheter 30 in afixed position relative to balloon 41.

[0032] Catheter securement device 24, (comprising torroidal balloon 41,support mount 42, pressure tube 43, and catheter guide 28), is adaptedto slide longitudinally within suspension housing 22. As can be seen inFIGS. 1 and 4, a groove 45 running longitudinally through suspensionhousing 22 provides freedom of longitudinal movement for pressure tube43, which passes therethrough, as shown.

[0033] In preferred aspects of the invention, torroidal balloon 41 ismade of silicon rubber, and support housing 22 and catheter guide 28 aremade either of aluminum, or a polycarbonate material. It is to beunderstood, however, that support housing 22 and catheter guide 28 canbe made of any suitable bio-compatible material.

[0034] Further structural details of the present invention are seen inthe exploded view of FIG. 1. A pair of fasteners 50 can be used tosecure housing flange 52 to supporting base 20. Backing plates 54 and 56can also be provided on opposite sides of catheter securement device 24.Backing plates 54 and 56 may preferably be made of aluminum. Fasteners58 can be provided for securing backing plates 54 and 56 to cathetersecurement device 24.

[0035] An alternate embodiment of the catheter securement device isshown in FIGS. 12 and 13. The system shown in FIGS. 12 and 13 operatessimilar to catheter system 24, moving to track movement of the patient'surethra, as explained herein. Instead of requiring a torroidal balloonand balloon support mount, a mechanical clamping system which moveslongitudinally is response to urethral movement is provided.

[0036] Referring to FIG. 12, a mechanical clamp 70 is provided. Clamp 70comprises a pair of hard opposite portions 72 and 74 supporting softinner surfaces 73 and 75 which may be manufactured of silicone ormedical tubing. A notch 71 is provided for supporting a catheter thereinas illustrated in FIG. 13. A spring 76 will bias hard opposite portions72 and 74 together, closing clamp 70 around a catheter received therein.As seen in FIG. 13, clamp 70 can be mounted to a backing 80, whereinbacking 80 moves longitudinally in suspension housing 22 under theinfluence of a biasing element, (functioning in the manner of biasingelement 26 as herein described). As can be seen, levers 77 and 79project out through groove 43. Pinching on levers 77 and 79 causesopposite portions 72 and 74 to separate, such that catheter 30 can bereceived therein. Levers 77 and 79 move longitudinally in groove 43 whencatheter groove 28 and backing 80 move in response to movement of thepatient's urethra. Clamp 70 may be secured to backing 80 by a pair ofpins 78. It is to be understood that other mechanical clamping systemsare possible, all keeping within the scope of the present invention,including the use of both expansion and compression springs to cause themechanical clamp to securely hold the catheter in position.

[0037] In a preferred aspect of the invention, optional leg straps areprovided for registering the supporting base 20 of catheter holder 10against the labia of the patient as catheter guide 28 moves with theurethra. Referring to FIG. 8, catheter holder 10 can be held in positionwith two leg straps 12 connected at opposite ends to supporting base 20,as shown. Alternatively, as shown in FIG. 9, a stretchable undergarment60 can be worn by the patient. Undergarment 60 has an opening 62 overwhich catheter holder 10 can be fastened in position by way of four legstraps 13, wherein each of leg straps 13 have a Velcro-type patch 15 attheir ends as shown for connecting fastening leg straps 13 directly tostretchable undergarment 60. Leg straps 12 may themselves be secured toslots 48 in supporting base 20 either by hooks (not shown) or by passingan end of each leg strap 12 through slot 60 and then folding the legstrap over upon itself and securing it into position with a Velcro-typefastener.

[0038] In another aspect of the present invention, a system forevaluating female urinary incontinence is provided. Preferably, thesystem for evaluating female urinary incontinence comprises the presenturethral catheter system as above described. Referring to FIG. 10,catheter 30 has pressure sensors 32 and 34 disposed thereon, as shown.Catheter 30 is preferably inserted through urethra 50 into bladder B.Catheter 30 is then controllably retracted through urethra 50 by amechanical retractor 60. Accordingly, pressure sensors 32 and 34 can bepositioned to take pressure measurements at each of the proximal urethraPU (which is located approximately 5-10 mm from the urethro-vesicularjunction U-VJ), the mid-urethra MU, (where the vesicle pressure isgreatest), to the distal urethra (which is located approximately 5-10 mmfrom the external meatus EM). It is to be understood that the presentinvention can operate with one or more pressure sensors 32 and 34 sincecatheter 30 can be retracted through urethra 50. As can be seen,supporting plate 20 rests against the patient's labia L.

[0039] In a preferred aspect, catheter 30 can comprise a catheterpositioning surface 31, such as an expandable balloon positioned betweenthe patient's distal urethra DU and external meatus EM to engage softtissues of urethra 50 so as to inhibit movement of catheter 30 withinurethra 50 when the patent coughs. Alternatively, the outer surface ofcatheter 30 can be textured so as to gently grip against the sides ofurethra 50, thereby holding catheter 30 in a fixed relative position tourethra 50. In a preferred aspect, a removable sheath is preferablyreceived over the high friction surface such that the catheter can beconveniently inserted into the patient and positioned at a desiredlocation. The sheath is then removed, such that the high frictionsurface of the catheter engages the walls of the urethra. Alternatively,fluid may be injected into the urethra, causing it to expand while thehigh friction surface catheter is inserted. Removal of the fluidsurrounding the catheter will cause the urethra to collapse inwardly,such that the high friction surface of the catheter engages the walls ofthe urethra.

[0040] The pressures measured by pressure sensor 30 are received bycomputer system 62 and are displayed as a pressuregram on displayterminal 64. FIG. 11 shows an exemplary pressuregram in which urethralpressure is plotted against vesicle pressure. The pressuregram shows therelationship between urethral and vesicle pressure for two differentpatients for different abdominal pressures caused by the patientcoughing. Patient A's urethral pressure always exceeds her vesiclepressure, therefore patient A remains continent. For patient “B”,however, her urethral pressure may be above or below her vesiclepressure, (as signified by her pressure data dropping below lineP_(urethral)−P_(vesicular)), thus indicating incontinence at certainabdominal pressures.

What is claimed is:
 1. A urethral catheter holder, comprising: asupporting base; a suspension housing mounted to the supporting base; acatheter securement device adapted to hold a catheter passinglongitudinally therethrough, the catheter securement device beingadapted to slide longitudinally within the suspension housing; and abiasing device adapted to push the catheter securement device againstthe external meatus of a patient's urethra.
 2. The catheter holder ofclaim 1, wherein the catheter securement device comprises: a torroidalballoon; a generally ring-shaped balloon support mount surrounding thetorroidal balloon; and a pneumatic or hydraulic pressure tube forinflating and deflating the torroidal balloon, the pressure tube passingthrough the balloon support mount.
 3. The catheter holder of claim 2,wherein, the pressure tube extends from the torroidal balloon to aposition external to the suspension housing.
 4. The catheter holder ofclaim 3, wherein the pressure tube moves longitudinally in a groove inthe suspension housing as the balloon support mount slideslongitudinally within the suspension housing.
 5. The catheter holder ofclaim 1, wherein, the catheter is received longitudinally through thesupporting base and the suspension housing.
 6. The catheter holder ofclaim 1, further comprising: a longitudinally extending catheter guidemounted to the catheter securement device.
 7. The catheter holder ofclaim 6, wherein, the catheter securement device is adapted to move inresponse to an abdominal pressure pulse.
 8. The catheter holder of claim7, wherein, the catheter securement device remains in generally the sameposition relative to a surrounding urethra when the patient coughs. 9.The catheter holder of claim 7, wherein, longitudinal displacement ofthe catheter securement device is approximately equal to longitudinaldisplacement of the urethra of a patient during the pelvic pressurepulse.
 10. The catheter holder of claim 1, wherein, the biasing deviceis a spring.
 11. The catheter holder of claim 2, wherein, the torroidalballoon is made of silicone rubber.
 12. The catheter holder of claim 1,wherein, the support housing is fabricated of aluminum or apolycarbonate material.
 13. The catheter holder of claim 1, wherein, thesupporting base is adapted to register against the labia of the patient.14. The catheter holder of claim 6, wherein, the catheter guide isadapted to contact the urethral external meatus of the patient.
 15. Thecatheter holder of claim 1, further comprising: a pair of leg straps,with opposite ends of each leg strap fastened to the supporting frame,such that each leg strap is adapted to be wrapped around one of thepatient's thighs.
 16. The catheter holder of claim 1, furthercomprising: a stretchable undergarment; and a plurality of leg straps,each leg strap being attachable to the supporting frame at one end andto the stretchable undergarment at an opposite end.
 17. The catheterholder of claim 16, wherein, each leg strap is attachable to thestretchable undergarment by a Velcro-type fastener.
 18. The catheterholder of claim 1, further comprising: a catheter retraction device forwithdrawing the catheter from the patient at a controlled speed.
 19. Asystem for evaluating female urinary incontinence, comprising: acatheter having at least one pressure sensor positioned thereon; and acatheter holder adapted to support the catheter and to allow movement ofthe catheter in response to a pelvic pressure pulse, wherein themovement of the catheter tracks movement of the urethra of a patientduring the pelvic pressure pulse.
 20. The system of claim 19, furthercomprising: a computer system in communication with the pressure sensorof the catheter, the computer system being adapted to generate apressuregram of the relationship between urethral pressure and vesiclepressure in response to changes in pelvic pressure as the pressuresensor on the catheter is moved through the urethra of a patient. 21.The system of claim 19 or 20, further comprising: a catheter retractiondevice for withdrawing the catheter to selectively position a pressuresensor on the catheter at each of proximal, mid and distal positionsalong the urethra.
 22. The system of claim 20, further comprising: adisplay terminal adapted to display the pressuregram.
 23. The system ofclaim 19, wherein the pressure sensing catheter comprises: a catheterpositioning surface positioned to engage soft tissues of the urethra soas to inhibit movement of the catheter within the urethra.
 24. Thesystem of claim 23, wherein the catheter positioning surface comprises:a high friction surface of the catheter for engaging the surroundingurethra.
 25. The system of claim 24, further comprising: a removablesheath positioned over the high friction surface of the catheter. 26.The system of claim 19, wherein the pressure sensing catheter comprises:a balloon positioned to engage soft tissues of the urethra so as toinhibit movement of the catheter within the urethra when the balloon isinflated.
 27. The urethral catheter of claim 1, wherein the cathetersecurement device comprises: a mechanical clamp adapted to belongitudinally movable within the suspension housing.
 28. The urethralcatheter of claim 27, wherein, the mechanical clamp is secured to alongitudinally movable backing.